(1) Field of the Invention
The present invention relates generally to circular knitted fabric and, more particularly, to a two end fleece, cotton/synthetic blend fabric having a weight of between about 8 to 12 oz. per sq. yd and improved pilling resistance.
(2) Description of the Prior Art
The term circular knitting covers those weft knitting machines having needle beds arranged in circular cylinders and/or dials including latch, bearded and occasionally compound needle machinery. Such machines produce a wide variety of fabric structures, garments, hosiery and other articles and a variety of diameters and machine gauges. Such machines have the needles fixed in a revolving circle with the loop formation and knitting action being achieved by ancillary elements moving yarn and loops along the needle stems producing a fabric tube with the technical face facing backwards.
Large diameter circular knitting machines are generally used to produce either fleece or jersey fabrics as well as other fabric constructions. Because of the seasonal nature of these fabrics, it is usually necessary to maintain both fleece and jersey machines on the knitting floor or to move machines in and out as seasonal fabric demands change. Both approaches are capital and labor cost intensive.
One approach to solving this problem is disclosed in U.S. Pat. No. 5,613,375, issued to Renda et al., the entire disclosure hereby being incorporated by reference. This patent teaches a new and improved circular knitting machine having interchangeable section blocks and sinkers which allow the machine to be converted between producing two end fleece and 4 track jersey fabrics by simply replacing the section blocks, carrier ring, needles and sinkers without the need to strip the machine to its bed or to change the feeders or creel.
The following discussion is taken generally from Spencer, David J., Knitting Technology, (2d. ed. 1989), which is a general treatment of knitting technology.
Knitted fabrics are progressively built up by converting newly fed yarn into new loops in the needle hooks, the needles then draw these new loops head first through the old loops, which have been retained from the previous knitting cycle. The needles at the same time release, cast off or knock-over old loops so that they hang suspended by their heads from the feet of the new loops whose heads are still held in the hooks of the needles. A cohesive structure is thus produced by a combination of the intermeshed loops and the yarn joining those loops together through which it passes.
Knitted loops are arranged in rows and columns roughly equivalent to the warp and weft of woven structures termed xe2x80x9ccoursesxe2x80x9d and xe2x80x9cwalesxe2x80x9d respectively. A course is a predominately horizontal row of loops (in an upright fabric) produced by adjacent needles during the same knitting cycle. A wale is a predominantly vertical column of needle loops produced by the same needle knitting at successive knitting cycles and thus intermeshing each new loop through the previous loop.
The term xe2x80x9cstitch densityxe2x80x9d is frequently used in knitting instead of a linear measurement of courses and wales; it is the total number of needle loops in a square area measurement such as square inch. It is obtained by multiplying, for example, the number of courses per inch by the number of wales per inch. Stitch density tends to be a more accurate measurement because tension acting in one direction in the fabric may, for example, produce a low reading for the courses and a high reading for the wales, which when multiplied together cancel the effect out.
xe2x80x9cYarn countxe2x80x9d indicates the linear density (yarn diameter or fineness) to which that particular yarn has been spun. The choice of yarn count is restricted by the type of knitting machine employed and the knitting construction. The yarn count, in turn, influences the cost, weight, opacity, handle and drapability of the resulting knitted structure. In general, staple spun yarns tend to be comparatively more expensive the finer their count, because finer fibers and a more exacting spinning process are necessary in order to prevent the yarn from showing an irregular appearance.
Historically, most systems are associated with particular yarn-spinning systems; for example, a yarn spun on the worsted system from acrylic fibers may be given a worsted count number. The worsted system is of the indirect type based on length per fixed unit mass, i.e., the higher the count number, the finer the yarn. The weight is fixed (1 lb.) and the length unit (number of 560-yard hanks) varies. 1/24""s worsted (24xc3x97560-hank yards weighing 1 lb.) will be twice the cross-sectional area of 1/48""s worsted (48xc3x97560-yard hanks weighing 1 lb.). 2/24""s worsted indicates that the yarn contains two ends of 1/24""s so that the resulting count is twice the cross-sectional area (24/2=12""s).
Three end and two end, course cut (10 to 14), knitting techniques are conventionally used to produce knitted fleece with low stitch densities (600-700). Fabric with a higher stitch density is generally perceived to be a higher quality fabric because it has a lower shrinkage rate and a more stable print platform. The term stable print platform is intended to be given its normal meaning, that is, a fabric that is sufficiently stable to be capable of receiving printed indicia or images and retaining those indicia or images during the normal course of wear and wash.
Two end, course cut knitting techniques are generally used to produce knitted fleece fabric with lower stitch density, which is generally perceived to be low quality fabric. Two end knitted fleece fabric constructions are typically less costly to produce compared to three end knitted fleece fabric constructions because of lower yarn material costs.
Both three end and two end course cut knitting techniques can be used to produce knitted fleece fabric having the same fabric weight and the same stitch density. However, because three end knitting uses three yarn ends, as opposed to two yarn ends used by two end knitting, a yarn having a finer yarn count, which is significantly more expensive, is necessary to produce knitted fleece fabric with the same fabric weight and same stitch density. Thus, it is much more costly to produce knitted fleece fabric of a given weight and stitch density using a three end knitting technique.
In addition, one well-known problem associated with knitted fabrics constructed of yarn that is a blend of cotton and polyester is pilling. Typically, in a blended yarn, the cotton fibers are not as strong relative to the polyester fibers. These cotton fibers have tendency to break when a garment, or other article, constructed of knitted fabric is worn, washed or is otherwise abraded. The cotton fibers then become attached to hook-like ends of the polyester fibers, resulting in small balls, or pills, of cotton fibers. Pilling is undesirable to consumers of products, such as apparel, made with knitted fabric constructed of blended yarn since the xe2x80x9cnewxe2x80x9d appearance of the garment is quickly loss. This is even more apparent in printed fabric since the printing quickly becomes fuzzy because of the pills.
One way to reduce pilling is to knit fabric from airjet spun yarn rather than open end spun yarn. Airjet spinning, however, disadvantageously requires equipment that is different than that used to produce open end spun yarn. The acquisition and maintenance of airjet spinning equipment adds considerably to the cost of yarn production and the knitted fabric which is made from the airjet spun yarn. For many existing plants converting to airjet spinning or buying airjet spun yarn would be cost prohibitive.
Thus, there remains a need for a new and improved knitted fleece, cotton/synthetic blend fabric that can be produced economically, and which has a relatively high stitch density and correspondingly low shrinkage rate and improved pilling resistance, and that has an extremely stable print platform. This has been found possible to achieve using a two end, fine cut (greater than about 14) knitting technique using more economical yarns than possible with three ends and a significantly higher stitch density and by reducing the amount of synthetic yarn in the face of the fabric below about 50 wt. %.
The present invention is directed to a stable print platform circular knitted fabric. In a preferred embodiment, the fabric has low shrinkage, low stretch and improved pilling resistance properties. The fabric is a two end fleece cotton/synthetic blend fabric having a weight of between about 8 to 12 oz. per sq. yd., a stitch density of between about 800 to 1000; and wherein the face of the fabric is about 25 wt. % synthetic for improving pilling resistance of the face of the fabric and the back of the fabric is about 75 wt. % synthetic for forming about a 50/50 total cotton/synthetic blend fabric. The face yarn count of the fabric is between about 16 to 20. In the preferred embodiment, the backing yarn count of the fabric is between about 7 to 12.
In the preferred embodiment, the fabric is formed from an acrylic-free cotton blend. Specifically, the fabric is formed from an acrylic-free cotton blend containing between about 50 to 90 percent cotton and the balance is polyester.
The resulting fabric construction of the present invention has stretch of less than about 3% stretch in the width direction and less than about 3% stretch in the length direction when tested according to a standard stretch chart. In addition, the fabric of the present invention has shrinkage in the range of less than 5% when tested according to a standard one wash cycle. The resulting fabric is an exceptionally stable print platform circular knitted fabric and has improved pilling resistance.
Accordingly, one aspect of the present invention is to provide a low-shrinkage, stable print platform circular knitted fabric The fabric includes (a) a two end fleece, cotton/synthetic blend fabric having a weight of between about 8 to 12 oz. per sq.yd.; and (b) a stitch density of greater than about 800, wherein the face of the fabric is less than 50 wt. % synthetic for improved pilling resistance of the face of the fabric.
Another aspect of the present invention is to provide a low-shrinkage, stable print platform circular knitted fabric. The fabric includes: (a) a two end fleece, cotton/synthetic blend fabric having a weight of between about 8 to 12 oz. per sq.yd.; and (b) a stitch density of between about 800 to 1000, wherein the face of the fabric is about 25 wt. % synthetic for improved pilling resistance of the face of the fabric and the back of the fabric is about 75 wt. % synthetic for forming about a 50/50 total cotton/synthetic blend fabric.
Still another aspect of the present invention is to provide a low-shrinkage, stable print platform circular knitted fabric. The fabric including: (a) a two end fleece, cotton/synthetic blend fabric having a weight of between about 8 to 12 oz. per sq.yd.; (b) a stitch density of between about 800 to 1000, wherein the face of the fabric is about 25 wt. % synthetic for improved pilling resistance of the face of the fabric and the back of the fabric is about 75 wt. % synthetic for forming about a 50/50 total cotton/synthetic blend fabric; and (c) wherein the denier of the face yarn of the fabric is greater than about 2 for further improved pilling resistance of the face of the fabric.